Curved die positioner

Abstract

A device and method for forming a removable die within a stone cast of a dental arch is presented. The die is attached to one end of a curved dowel pin which in turn slides into a curved channel in the base of the stone cast. The unique curved path of insertion and removal allow the die to be repositioned accurately and held securely with a single dowel.

What is claimed is: 
     
       1. A curved metal dowel pin for removably joining a dental die to a dental cast, said dowel having a notched or knurled head at one end for embedding in said die, and a smooth shank extending from said head and being uniformly curved substantially throughout its length for sliding into a similarly shaped channel in said dental cast, said shank terminating in a tip which is smaller in diameter than the entrance of the channel. 
     
     
       2. A curved dowel pin as in claim 1 in combination with one or more retaining pins, said dowel pin having one or more holes drilled into its shank to receive said retaining pins in such a way that the retaining pins project inside the curve of said dowel pin for attachment of said curved dowel pin to a dental impression. 
     
     
       3. A curved dowel pin as in claim 1 in combination with a sleeve and one or more retaining pins, said sleeve having a longitudinal curved channel to receive the curved shank of the dowel pin and one or more transverse perforations from which said retaining pins project and are generally parallel to the plane of curvature, to each other, and to the head of the curved dowel pin. 
     
     
       4. A method of forming a removable dental die comprising the steps of: (a) positioning a curved dowel pin, having a head and a shank extending from said head and being uniformly curved throughout its length, over a dental impression with the head of the dowel pin inside the impression of the selected tooth and securing said curved dowel pin to the impression by means of one or more retaining pins with one end of each attached to the curved dowel and the other end inserted into the border of the impression.   (b) pouring die-forming material into the impression so that it slightly overfills the impressions of the teeth and covers the notched head of the curved dowel,   (c) coating the exposed shank of the curved dowel and the surrounding hardened die material with a separating agent, such as petrolatum,   (d) filling the rest of the impression with dental stone so that it covers the shank of the curved dowel except for its tip,   (e) separating the die from the rest of the hardened stone cast by sawing through the die material on either side of the replica of the selected tooth to the level of the separating agent and tapping the small protruding end of the curved dowel.   
     
     
       5. A method of forming a removable dental die comprising the steps of: (a) pouring a die-formng material into a dental impression to a level a few millimeters above the necks of the teeth,   (b) drilling a hole in the top of the hardened die material directly over the replica of the tooth being treated,   (c) providing a curved dowel pin having a head and a shank extending from said head and being uniformly curved substantially throughout its length,   (d) cementing the head of said curved dowel pin into the previously drilled hole so that the shank of the dowel curves upward and laterally,   (e) coating the shank of the curved dowel and the surrounding die material with a separating agent,   (f) pouring a base of dental stone on top of the die material so that the curved dowel is completely covered except for its tip which is left protruding from the side of the base,   (g) separating the die from the rest of the hardened stone cast by sawing through the die material on either side of the replica of the selected tooth to the level of the separating agent and tapping the small protruding end of the curved dowel.